-------------------------------------------------------------------------
-- Receives messages from around the network and routes to destination
-------------------------------------------------------------------------

-- Define routing table
tRoute =
{
  {dest="CMD", address="643bec2f-3776-4de0 895e-43a40a677a36", via="MODEM", desc="Command Line Server"},
  {dest="VOM", address="9a405bde-647a-4593-acb5-9a5d8251f8e1", via="TUNNEL", desc="Void Ore Miner"},
  {dest="VRM", address="9a405bde-647a-4593-acb5-9a5d8251f8e1", via="TUNNEL", desc="Void Resource Miner"}
}

-- Constants
ciPort=1001 -- Port used globally on my network

-- Open modem and tunnel
local oComponent = require("component")
local oEvent = require("event")
local oModem = oComponent.modem
local oTunnel = oComponent.tunnel
local oTerm = require("term")
local oSerialization = require("serialization")

oModem.open(ciPort)
-- Do not have to open linked card - always open

if not oModem.isOpen(ciPort) then
  print("Modem failed to open on port " .. ciPort .. ". Exiting...")
  os.exit()
end

-------------------------------------------------------------------------
-- Functions

function FindDest(psDest, ptRoute)
local lsAddress = ""
local lsVia = ""
local lsDesc = ""

  -- Check the routing table and find the details of the destination
  for i, row in ipairs(ptRoute) do
    if row.dest == psDest then
      lsAddress = row.address
      lsVia = row.via
      lsDesc = row.desc
    end
  end

  -- Check for dest unknown
  if lsAddress == "" then
    lsDesc = "Unknown Address"
  end

  -- Return values to calling function
  return lsAddress, lsVia, lsDesc
end

function ParseMsg(psMsgRaw)
local loS = require("serialization")

  -- Parse the raw message into a destination and a command

  local ltMsg = loS.unserialize(tostring(psMsgRaw))
  local lsDest = ltMsg.dest
  local lsCmd = ltMsg.cmd

  -- Return values to calling function
  return lsDest, lsCmd
end

-------------------------------------------------------------------------
-- Main Program

local fContinue = true
local fLog = true
local lsDest = ""
local lsMsg = ""

-- Clear the screen
oTerm.clear()
print("Initialising message routing...")

-- Enter Loop
while fContinue do
  -- Wait for an inbound message
  _, _, _, _, _, sMsgRaw = oEvent.pull("modem_message")

  -- Parse message
  lsDest, lsCmd = ParseMsg(sMsgRaw)

  -- Check for debug/local command
  if lsDest == "LCL" then
    -- Check to log
    if fLog then print("CMD " .. sMsgRaw) end
    -- Check for program quit
    if lsCmd == "EXIT" then fContinue = false end
    if lsCmd == "LOG" then
      fLog = true
      print("CMD Enable Logging")
    end
    if lsCmd == "NOLOG" then
      fLog = false
      print("CMD Disable Logging")
    end
    if lsCmd == "LIST" then
      lsCmd = oSerialization.serialize(tRoute)
      lsDest = "CMD"
    end
  end
  -- Message to process/send
  if lsDest ~= "LCL" or (lsDest == "LCL" and lsCmd == "LIST") then
    -- Get the destination etc
    lsAddress, lsVia, lsDesc = FindDest(lsDest, tRoute)

    -- Check to log
--    if fLog then print("Sending command " .. lsCmd .. " via " .. lsVia .. " to " .. lsDest .. ":" .. lsDesc) end

    -- Check for unknown destination
    if lsDesc == "Unknown Address" then
      -- Print the details
      print("Unknown Address")
      -- Send a message to the control computer

    else
      -- Check path
      if lsVia == "MODEM" then       -- Route via modem
        oModem.send(lsAddress, ciPort, lsCmd)
      else                          -- Route via linked card
        oTunnel.send(lsCmd)
      end
    end
  end                             -- If local/forward

  -- Yield for a little bit
  os.sleep(0.1)
end